Method for operating a landing gear and an aircraft including the landing gear

ABSTRACT

A method for operating a landing gear. The method includes extending an actuator to apply a force to a crank link of a toggle lock mechanism causing a mechanical unlocking of a second lock link from a fully extended position, retracting the actuator to rotate the toggle lock mechanism about a toggle lock pivot axis of a first lock link, causing rotation of the second lock link that is rotatably coupled to the first lock link so that the second lock link folds relative to the first lock link in a second rotation direction, and a toggle link of the toggle lock mechanism rotates relative to the second lock link, in the first rotation direction opposite the second rotation direction, to rotate the second lock link to a fully retracted position of the second lock link relative to the first lock link.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims the benefit of U.S.Non-Provisional patent application Ser. No. 15/255,698 filed on Sep. 2,2016 (now U.S. Pat. No. ______ issued on ______), the disclosure ofwhich is incorporated by reference herein in its entirety.

BACKGROUND 1. Field

The exemplary embodiments generally relate to aircraft landing gearcomponents and systems and in particular to landing gear lock assembliesfor extending and retracting landing gear.

2. Brief Description of Related Developments

Landing gear toggle lock mechanisms must lock the landing gear sideand/or drag braces into the landing gear extended position. The togglelock mechanisms are designed to lock into place using spring force wheresprings apply force to the toggle locking mechanism to achieve thelocked position. New landing gears, for example on commercial aircraft,require more locking force from the springs than is available withconventional landing gear toggle lock mechanisms due to spacelimitations onboard the aircraft and strength of materials available.

At least one known toggle lock mechanism includes an outboard lock link,an inboard lock link, an upper toggle, a lower toggle, one or moresprings, and an actuator. Such a toggle lock mechanism uses the one ormore springs to lock the landing gear in the landing gear extendedposition and uses the actuator to unlock the landing gear against theforce of the one or more springs. During extension, the upper and lowertoggles unfold in the same direction as the lock links. This system isconfigured to apply locking force to the toggle mechanism forapproximately 90% of the landing gear extension stroke, whereas theforce is only used in the last approximately 10% of the landing gearextension stroke. Springs for this toggle lock mechanism have a muchlonger spring stroke than may be necessary, which can waste a majorityof the spring stroke and thus, wasting a majority of the energy storedin the springs. Also, in such landing gear toggle lock mechanisms, thesprings are under load (e.g., extended) while the landing gear isretracted reducing the life of the springs.

SUMMARY

The following is a non-exhaustive list of examples, which may or may notbe claimed, of the subject matter according to the present disclosure.

One example of the subject matter according to the present disclosurerelates to a landing gear lock assembly including a first lock linkhaving a first end and a second end, a second lock link having a firstend and a second end, the first end of the second lock link beingrotatably coupled to the second end of the first lock link so that thefirst and second lock links unfold relative to each other in a firstrotation direction, and a toggle lock mechanism having a crank link anda toggle link rotatably coupled to each other at a toggle link axis, thetoggle link being rotatably coupled to the second lock link, and thecrank link being rotatably coupled to the first lock link so that thetoggle link rotates relative to the second lock link, in a secondrotation direction opposite the first rotation direction, to rotate thesecond lock link to a fully extended position of the second lock linkrelative to the first lock link, where rotation of the toggle link inthe second rotation direction mechanically locks the second lock link inthe fully extended position.

Another example of the subject matter according to the presentdisclosure relates to a method of assembling a landing gear lockassembly, the method including rotatably coupling a second end of afirst lock link to a first end of a second lock link so that the firstand second lock links unfold relative to each other in a first rotationdirection, rotatably coupling a crank link and a toggle link of a togglelock mechanism to each other, rotatably coupling the toggle link to thesecond lock link and rotatably coupling the crank link to the first locklink so that the toggle link rotates relative to the second lock link,in a second rotation direction opposite the first rotation direction, torotate the second lock link to a fully extended position of the secondlock link relative to the first lock link, and wherein the second locklink mechanically locks in the fully extended position with rotation ofthe toggle link in the second rotation direction.

Still another example of the subject matter according to the presentdisclosure relates to a method for operating a landing gear, the methodincluding extending an actuator to rotate a toggle lock mechanism abouta toggle lock pivot axis of a first lock link, causing rotation of asecond lock link that is rotatably coupled to the first lock link sothat the second lock link unfolds relative to the first lock link in afirst rotation direction, and a toggle link of the toggle lock mechanismrotates relative to the second lock link, in a second rotation directionopposite the first rotation direction, to rotate the second lock link toa fully extended position of the second lock link relative to the firstlock link, and applying a force to a crank link of the toggle lockmechanism with at least one biasing member to further rotate the togglelock mechanism in the second rotation direction causing rotation of thesecond lock link to the fully extended position and causing a mechanicallocking of the second lock link in the fully extended position, whereinthe toggle link couples the crank link to the second lock link, theactuator is coupled to both the first lock link and the crank link, andthe at least one biasing member is coupled to both the first lock linkand the crank link.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described examples of the present disclosure in generalterms, reference will now be made to the accompanying drawings, whichare not necessarily drawn to scale, and wherein like referencescharacters designate the same or similar parts throughout the severalviews, and wherein:

FIG. 1A is a schematic illustration of an aircraft in accordance withone or more aspects of the present disclosure;

FIG. 1B is a schematic illustration of a portion of an aircraft landinggear in accordance with one or more aspects of the present disclosure;

FIG. 1C is a schematic illustration of a portion of an aircraft landinggear in accordance with one or more aspects of the present disclosure;

FIGS. 2A-2D are schematic illustrations of a landing gear lock assemblyin accordance with one or more aspects of the present disclosure;

FIGS. 3A-3E are schematic illustrations of an unfolding sequence of alanding gear lock assembly in accordance with one or more aspects of thepresent disclosure;

FIGS. 4A-4C are schematic diagrams of the landing gear lock assembly inaccordance with one or more aspects of the present disclosure;

FIG. 5 is a schematic diagram of the landing gear lock assembly inaccordance with one or more aspects of the present disclosure;

FIGS. 6A-6B are schematic diagrams of the landing gear lock assembly inaccordance with one or more aspects of the present disclosure;

FIG. 7 is a flow chart of a method of assembly of a landing gear lockassembly in accordance with one or more aspects of the presentdisclosure;

FIG. 8 is a flow chart of a method of extension of a landing gear lockassembly in accordance with one or more aspects of the presentdisclosure;

FIG. 9 is a flow chart of a method of retraction of a landing gear lockassembly in accordance with one or more aspects of the presentdisclosure;

FIG. 10 is a block diagram of aircraft production and servicemethodology.

DETAILED DESCRIPTION

The embodiments described herein may provide an improved landing geartoggle lock mechanism which has a more compact configuration, reducedweight and that generally applies a largest amount of spring force at apredetermined point of extension of the landing gear.

Illustrative, non-exhaustive examples, which may or may not be claimed,of the subject matter according to the present disclosure are providedbelow.

Referring to FIGS. 1A-1C and 2A-2D an exemplary landing gear lockassembly 100 is illustrated incorporating aspects of the presentdisclosure.

In one aspect, while the landing gear lock assembly 100 described hereinis described with respect to a commercial passenger jet, referred toherein as the aircraft 1102, in other aspects the aircraft may be anysuitable fixed wing or rotary wing aircraft. The landing gear lockassembly 100 may also be used in landing gear 1100 having any suitableposition on the aircraft 1102, such as landing gear 1100A, which may bea main landing gear, located towards a longitudinal center of theaircraft 1102, nose landing gear 1100B located towards a longitudinalfront of the aircraft 1102 or in other aspects, tail landing gear 1100Clocated towards the rear or tail of the aircraft 1102. As will bedescribed herein the landing gear lock assembly 100 is a self-containedassembly that is configured to couple to one or more of the airframe1118 and the landing gear components of the aircraft 1102 for lockingthe landing gear 1100 in an extended position. For example, the landinggear lock assembly 100 is configured to couple to a landing gear shockstrut 1140 and the links 1142 a-b, 1144 a-b of a respective landing gearbrace, such as a landing gear drag brace 1142 or landing gear side brace1144.

In one aspect, the landing gear lock assembly 100 described hereinincludes a toggle tock mechanism for landing gears that use foldingbrace elements such as, e.g., the landing gear drag brace 1142 orlanding gear side brace 1144. The landing gear lock assembly 100 uses atleast one biasing member to lock the landing gear in the landing gearextended position and uses an actuator to unlock the landing gearagainst the force of the at least one biasing member. The landing gearlock assembly 100 can provide for the use of reduced power biasingmembers, when compared to conventional landing gear lock designs, has areduced size compared to conventional landing gear lock designs, andincludes fewer parts than conventional landing gear lock designs thatperform the same or similar function (e.g., locking landing gear in anextended position or configuration). As such, the aspects of the landinggear lock assembly 100 described herein may reduce weight of theaircraft 1102 due, e.g., to the smaller size of the landing gear lockassembly 100, and may reduce cost of the aircraft 1102 due to, e.g., thereduced number of parts included in the landing gear lock assembly 100.

As described herein, the landing gear lock assembly 100 includes atoggle lock mechanism that unfolds in a direction opposite to theunfolding direction of the first lock link and the second lock link. Theconfiguration of the toggle lock mechanism described herein causes lostmotion in the toggle mechanism and the at least one biasing member sothat the at least one biasing member substantially may not extend orretract through a portion of the landing gear extension and retraction(e.g. unfolding and folding) sequence. As described herein the at leastone biasing member is in a relaxed state (e.g. substantially retractedwhere the biasing member may exhibit only enough force so that the atleast one biasing member remains coupled to the toggle lock mechanism)when the landing gear is fully extended and when the landing gear isfully retracted.

The landing gear lock assembly 100 is configured so that the at leastone biasing member contracts from a maximum length substantially at theend of the landing gear extension sequence, applying a locking force tothe landing gear, so that a maximum tension force on the biasing membermay be near the optimum point in landing gear extension as describedherein.

Referring to FIGS. 2A-2D, in one aspect, the landing gear lock assembly100 includes a first lock link 101 having a first end 101 a and a secondend 101 b, a second lock link 102 having a first end 102 a and a secondend 102 b, and a toggle lock mechanism 103. In one aspect, the landinggear lock assembly 100 also includes at least one biasing member 106 andat least one actuator 107.

In one aspect, the first end 102 a of the second lock link 102 isrotatably coupled to the second end 101 b of the first lock link 101 ata link pivot axis LPA. In one aspect, the link pivot axis LPA isdisposed substantially adjacent the first end 102 a of the second locklink 102 and the second end 101 b of the first lock link 101. In oneaspect, the link pivot axis LPA is disposed between the first end 102 aand the second end 102 b of the second lock link 102. The first andsecond lock links 101, 102 are rotatably coupled to each other so as tounfold relative to each other about the link pivot axis LPA, i.e., asthe landing gear lock assembly 100 unfolds, the second lock link 102rotates relative to the first lock link 101 in a first rotationdirection R1.

Referring still to FIGS. 2A-2D, in one aspect, the toggle lock mechanism103 includes a crank link 104 and a toggle link 105 and is coupled toboth the first lock link 101 and the second lock link 102. In oneaspect, the crank link 104 has a first end 104 a and a second end 104 band a toggle lock pivot axis TLPA disposed between the first end 104 aand second end 104 b. The crank link 104 is rotatably coupled to thefirst lock link 101, between the first and second ends 101 a, 101 b ofthe first lock link 101 about the toggle lock pivot axis TLPA.

In one aspect, a first end 105 a of the toggle link 105 is rotatablycoupled to the crank link 104 about a first toggle link axis TA1 and asecond end 105 b of the toggle link is rotatably coupled to the secondlock link 102 about a second toggle link axis TA2. In one aspect, thefirst toggle link axis TA1 is located substantially adjacent the firstend 104 a of the crank link 104 and adjacent the first end 105 a of thetoggle link 105. In one aspect, the first toggle link axis TA1 islocated between the first end 104 a and the toggle lock pivot axis TLPAof the crank link 104. In one aspect, the second toggle link axis TA2 islocated adjacent the first end 102 a of the second lock link 102 andadjacent the second end 105 b of the toggle link 105.

The toggle link 105 is configured to rotate relative to the second locklink 102, in a second rotation direction R2 opposite the first rotationdirection R1. Rotating the toggle link 105 relative to the second locklink 102 in the second rotation direction R2 causes the crank link 104and the toggle link 105 of the toggle lock mechanism 103 to unfold in arotation direction R5 opposite the first rotation direction R1, whichcan provide for a more compact landing gear toggle lock mechanismconfiguration than that of a conventional landing gear lock. Asdescribed herein, the rotation of the toggle link 105 in the directionR2, combined with the rotation of the crank link 104, rotates the secondlock link 102 to a fully extended position relative to the first locklink 101 and mechanically locks the second lock link 102 in the fullyextended position.

In one aspect, the mechanical locking of the second lock link 102 in thefully extended position is caused by an over center locking of thetoggle link 105 and crank link 104. In one aspect, the crank link 104includes a toggle stop 110 configured to contact the toggle link 105 atthe over center locked position 100L (see FIG. 2D) of the landing gearlock assembly 100. When the toggle stop 110 is in contact with thetoggle link 105, the landing gear lock assembly 100 is mechanicallylocked in the extended position.

Still referring to FIGS. 2A-D, the landing gear lock assembly 100includes at least one biasing member 106 that is coupled to both thefirst lock link 101 and the crank link 104. In one aspect, the at leastone biasing member 106 is an extension spring. In another aspect, the atleast one biasing member 106 is a coil/torsion spring 106′. It should beunderstood that the at least one biasing member 106 may be any suitablebiasing member(s) (e.g. tension, compression, or torsion) that applies alinear or rotational biasing force, e.g., moment M, between the firstlock link 101 and the crank link 104.

In one aspect, a first end 106 a of the at least one biasing member 106is coupled to the first lock link 101 and a second end 106 b of the atleast one biasing member 106 is coupled to the crank link 104. In oneaspect, the first end 106 a of the at least one biasing member 106 iscoupled to the first lock link 101 adjacent the first end 101 a of thefirst lock link 101 and the second end 106 b of the biasing member 106is coupled to the crank link 104 adjacent the second end 104 b of thecrank link 104.

In a particular aspect, the at least one biasing member 106 is locatedon a side of the first lock link 101 opposite a sweep path SP of thesecond lock link 102, which provides clearance for the second lock link102 to sweep or rotate into an extended or retracted configuration andalso provides compactness of the landing gear lock assembly 100.Locating the at least one biasing member 106 on the side of the firstlock link 101 opposite the sweep path SP of the second lock link 102also provides for a longer crank link 104 to increase the moment M andhence increase the locking force applied by the at least one biasingmember 106.

The at least one biasing member 106 is in a substantially relaxed statewhen the second lock link 102 is in a fully retracted position (as shownin FIG. 2A), which can provide less stress on the at least one biasingmember 106, reduce fatigue on the at least one biasing member 106,and/or increase the life of the at least one biasing member 106.

The at least one biasing member 106 is in a substantially relaxed statewhen the second lock link 102 is in the fully extended position (asshown in FIG. 3E) which also provides less stress on the at least onebiasing member 106, reduces fatigue on the at least one biasing member106 and increases the life of the at least one biasing member 106.

In a particular aspect, as shown in FIG. 2A and described herein, the atleast one biasing member 106 is configured to apply a moment M of forceto the crank link 104 of the toggle lock mechanism 103 to cause rotationof the crank link 104 about toggle lock pivot axis TLPA. Rotation of thecrank link 104 in direction R4 causes toggle link 105 to push on thesecond lock link 102 and rotate the second lock link 102 about axis LPAto the fully extended position of the second lock link 102. It is notedthat rotation of the crank link 104 to lock the toggle lock mechanism103 causes rotation of the toggle link 105 in the direction R2, relativeto the second lock link 102, which as noted here is opposite to thedirection of rotation R1 of the second lock link 102.

In a particular aspect as shown in FIGS. 2C and 6B, the at least onebiasing member 106 includes two or more biasing members 106D-106F. Eachof the two or more biasing members 106D-106F being substantially similarto the at least one biasing member 106 described above. While threebiasing members are shown for exemplary purposes in other aspects, theremay be more than three biasing members. In one aspect, the two or morebiasing members 106D-106F are arranged in parallel and located on acommon side of the first lock link 101, in a manner similar to thatdescribed above, which provides a more compact configuration of thelanding gear lock assembly 100 compared to the conventional toggle lockmechanism.

In a particular aspect shown in FIGS. 2A-2D, the landing gear lockassembly 100 includes but one set of biasing members 106S coupled toboth the first lock link 101 and the crank link 104, such that the butone set of biasing members 106S is the only set of biasing members 106of the landing gear lock assembly 100. The but one set of biasingmembers 106S is located on a single or common side of the first locklink 101 in a manner similar to that described above. The but one set ofbiasing members 106S is substantially similar to the at least onebiasing member 106 described above. Having but one set of biasingmembers 106S can provide a more compact configuration and may alsoreduce weight of the landing gear lock assembly 100 compared to, e.g., aconventional toggle lock mechanism.

Still referring to FIGS. 2A-D, the landing gear lock assembly 100includes at least one actuator 107 coupled to both the first lock link101 and the crank link 104. In one aspect, the actuator 107 includes afirst end 107 a coupled to the first lock link 101 and a second end 107b coupled to the crank link 104. The actuator is coupled to the firstlock link 101 adjacent the first end 101 a of the first lock link 101,but the actuator 107 may alternatively be coupled to any suitablelocation of the first lock link 101.

In one aspect, the first lock link 101 includes a recess or channel 109,the at least one actuator 107 being disposed within the recess 109,which can provide for a more compact configuration of the landing gearlock assembly 100 compared to a conventional toggle lock mechanism.

Referring also to FIGS. 4A-4C, the actuator 107 is coupled to the cranklink 104 adjacent the first end 104 a of the crank link 104 so that aforce applied on the crank link 104 by the at least one biasing member106 is on an opposite side of the crank link 104, relative to the togglelock pivot axis TLPA, than a force applied to the crank link 104 by theactuator 107 (i.e. the at least one biasing member 106 and the actuator107 are connected to the crank link 104 on opposite sides of the togglelock pivot axis TLPA). In order to release the over center lockedposition 100L of the toggle lock mechanism 103, the at least oneactuator 107 is configured to pull the first end 104 a of the crank link104 against the force of the at least one biasing member 106 beingapplied to the second end 104 b of the crank link 104. Unlocking theover center locking allows the second lock link 102 to be retracted inany suitable manner to the fully retracted position.

In other aspects, referring now also to FIG. 5, the at least one biasingmember 106 and the at least one actuator 107 are coupled to a commonside, e.g., the second end 104 b, of the crank link 104 relative to thetoggle lock pivot axis TLPA. Here, the at least one actuator 107 isconfigured to push the crank link 104 against the force of the at leastone biasing member 106 to release the locked toggle lock mechanism 103.

In other aspects, referring now also to FIG. 6A-6B, the two or morebiasing members 106D-E are located on opposite sides of the first locklink 101 and the at least one actuator 107 is located between the two ormore biasing members 106D-E. In this aspect, the at least one actuator107 and two or more biasing members 106D-E cross one another so that theactuator 107 applies force to the second end 104 b of the crank link 104and two or more biasing members 106D-E apply force to the first end 104a of the crank link 104 (e.g., on opposites sides of the toggle lockpivot axis TLPA). Here, the actuator 107 pulls the crank link 104 torelease the over center locking of the toggle lock mechanism 103. Thecrossed configuration may provide the at least one actuator 107 with agreater mechanical advantage, e.g., requiring less pull force to unlockthe over center locked toggle lock mechanism 103 to reduce the size ofactuator 107.

Referring now to FIGS. 2A-2D and 7, a method 700 for assembling thelanding gear lock assembly 100 includes rotatably coupling the secondend 101 b of the first lock link 101 to the first end 102 a of thesecond lock link 102 at a link pivot axis LPA disposed between the firstend 102 a and the second end 102 b of the second lock link 102 so thatthe first and second lock links 101, 102 unfold relative to each otherin the first rotation direction R1 (FIG. 7, Block 701). The crank link104 and the toggle link 105 of the toggle lock mechanism 103 arerotatably coupled to each other about the first toggle link axis TA1(FIG. 7, Block 702). The toggle link 105 is rotatably coupled to thesecond lock link 102 about the second toggle link axis TA2 and the cranklink 104 is rotatably coupled to the first lock link 101 about thetoggle lock pivot axis TLPA so that the toggle link 105 rotates relativeto the second lock link 102, in the second rotation direction R2opposite the first rotation direction R1. As described herein, thetoggle link 105 is coupled to the crank link 104 and second lock link102 to rotate the second lock link 102 about the link pivot axis LPA toa fully extended position of the second lock link 102 relative to thefirst lock link 101 (FIG. 7, Block 703).

In one aspect, assembling the landing gear lock assembly 100 includescoupling the at least one biasing member 106 to both the first lock link101 and the crank link 104, such as in one of the configurationsdescribed above with respect to FIGS. 2A, 5, and 6A. For example,assembling the landing gear lock assembly 100 includes coupling the butone set of biasing members 106S to both the first lock link 101 and thecrank link 104 so that the but one set of biasing members 106S arelocated on a common side of the first lock link 101.

In one aspect, assembling the landing gear lock assembly 100 includesdisposing the at least one actuator 107 within the recess 109 of thefirst lock link 101 and coupling the at least one actuator 107 to boththe first lock link 101 and the crank link 104, such as in one of theconfigurations described above with respect to FIGS. 2A, 5, and 6A. Forexample, assembling the landing gear lock assembly 100 includes couplingthe first end 107 a of the at least one actuator 107 to the first locklink 101 and the second end 107 b of the at least one actuator 107 tothe crank link 104.

In one aspect, assembling the landing gear lock assembly 100 includescoupling the at least one actuator 107 to both the first end 104 a ofthe crank link 104 and the first lock link 101, and coupling the atleast one biasing member 106 to both the first lock link 101 and thesecond end 104 b of the crank link 104. Here, the first and second ends104 a, 104 b of the crank link 104 are disposed on opposite sides of thetoggle lock pivot axis TLPA as shown in, e.g., FIGS. 2A-2D.

In one aspect, assembling the landing gear lock assembly 100 includescoupling the at least one actuator 107 to both the second end 104 b ofthe crank link 104 and the first lock link 101, and coupling the atleast one biasing member 106 to both the second end 104 b of the cranklink 104 and the first lock link 101. Here, the at least one actuator107 and the at least one biasing member 106 are coupled on the same sideof the toggle lock pivot axis TLPA as shown in, e.g., FIG. 5.

In one aspect, assembling the landing gear lock assembly 100 includescoupling the at least one actuator 107 to both the first end 104 a ofthe crank link 104 and the first lock link 101, and coupling the atleast one biasing member 106 to both the second end 104 b of the cranklink 104 and the first lock link 101. Here, the at least one actuator107 and the at least one biasing member 106 cross one another and applyforces on opposite sides of the toggle lock pivot axis TLPA as shown in,e.g., FIGS. 6A and 6B.

Referring again to FIGS. 1A-1C and 2A-2D, the first end 101 a of thefirst lock link 101 is configured for coupling to a landing gear shockstrut 1140 of the aircraft 1102 or to an aircraft frame or airframe1118. In one aspect, the landing gear shock strut 1140 is located on themain landing gear 1100A, the nose landing gear 1100B, the tail landinggear 1100C, or any other suitable landing gear of the aircraft 1102. Inone aspect, the second end 102 b of the second lock link 102 isconfigured for coupling to one of a landing gear drag brace 1142 orlanding gear sides brace 1144. In other aspects, the second end 102 b ofthe second lock link 102 is configured to couple to the landing gearshock strut 1140 or the airframe 1118 and the first end 101 a of thefirst lock link 101 is configured to couple to the landing gear dragbrace 1142 or the landing gear side brace 1144.

As can be seen in FIGS. 1B-1C, 2A-2D, and 3A-3E and described above, thelanding gear lock assembly 100 is a self-contained locking assemblyfunctionally coupled to the aircraft 1102 by only the first lock link101 and second lock link 102. The landing gear lock assembly 100 isself-contained, such that the at least one biasing member 106, at leastone actuator 107, and the toggle lock mechanism 103 are allself-contained as a unit with the first and second lock links 101, 102and are installed and removed from the aircraft 1102 as a unit and onlycoupled to the aircraft 1102 by the first and second lock link 101, 102.

Referring now to FIGS. 1A-1C, 3A-3E, 4A-C and 8, a method 800 foroperating, for example, landing gear 1100A is illustrated. In oneaspect, the landing gear 1100A is situated in a retracted/foldedposition within the airframe 1118. While the landing gear 1100A is in aretracted position, the landing gear lock assembly 100 is also in aretracted position as illustrated in FIGS. 1C and 3A.

The landing gear 1100 is extended by actuating any suitable actuator,such as landing gear actuator 1145 (see FIG. 1B), and/or by gravity.Extending the landing gear, with an actuator and/or by gravity, causesextension of the landing gear lock assembly 100 where actuator 107 isextended to cause rotation of the toggle lock mechanism 103 about thetoggle lock pivot axis TLPA of the first lock link 101. In one aspect,gravitational forces acting on the landing gear cause extension of theactuator 107. Rotation of the toggle lock mechanism 103 in turn causesrotation of the second lock link 102, which is rotatably coupled to thefirst lock link 101 (FIG. 8, Block 801). As the second lock link 102rotates, the second lock link 102 unfolds relative to the first locklink 101 in the first rotation direction R1 (FIG. 8, Block 802). Thetoggle link 105 of the toggle lock mechanism 103 rotates relative to thesecond lock link 102, in the second rotation direction R2 opposite thefirst rotation direction R1, rotating the second lock link 102 to afully extended position relative to the first lock link 101 (FIG. 8,Block 803); where the crank link 104 and the toggle link 105 unfold in adirection opposite the lock links 101, 102. A moment M is applied to thecrank link 104 of the toggle lock mechanism 103 with the at least onebiasing member 106 and further rotates the toggle lock mechanism 103 inthe second rotation direction R2. Further rotating the toggle lockmechanism 103 causes rotation of the second lock link 102 to the fullyextended position and causes a mechanical locking of the second locklink 102 (FIG. 8, Block 804).

As illustrated in FIGS. 3A-3E and 4A-4C, transitioning the landing gearlock assembly 100 from a retracted position to an extended position overa sweep angle θ of the second lock link 102 causes a stretching of theat least one biasing member 106 from a substantially relaxed andretracted configuration (FIG. 3A) to an extended configuration (FIGS.3B-3D) and back to a substantially relaxed and retracted configuration(FIG. 3E). In a particular aspect, the second lock link 102 has a sweepangle θ of about 150 degrees from a fully retracted position to fullyextended position; however, in other aspects the sweep angle θ of thesecond lock link 102 may be more or less than about 150 degrees.

As seen in FIG. 3A, the landing gear lock assembly 100 is in a retractedposition and the at least one biasing member 106 is in a relaxed andretracted configuration (i.e. a minimum length). When the landing gearlock assembly 100 is unfolded from the retracted position, the cranklink 104 of the toggle lock mechanism 103 begins rotation in therotation direction R3 about toggle link axis TLPA relative to the firstlock link 101 and the second lock link 102 begins rotation in rotationdirection R1 about link pivot axis LPA. The at least one biasing member106 transitions from a minimum length at the retracted configuration toa maximum length, as seen in FIGS. 3B and 4A. When the at least onebiasing member is at the maximum length the landing gear brace has abrace angle α of, for example, about 150 degrees. In other aspects, thebrace angle α may be more or less than about 150 degrees. The maximumlength of the at least one biasing member 106 may be a full ratedextension length, which is described in greater detail below. In anotheraspect, the maximum length of the at least one biasing member 106 may bea length defined by a bi-directional rotational movement of the cranklink 104.

The crank link 104 of the toggle lock mechanism 103 bi-directionallyrotates relative to the first lock link 101 during the extension of thelanding gear lock assembly 100, while the toggle link 105 rotates inrotation direction R2 relative to the second lock link 102 throughoutthe extension of the landing gear lock assembly 100. For example, thecrank link 104 may rotate in rotation direction R3 about toggle linkpivot axis TLPA to a point in the extension of the landing gear lockassembly 100 (e.g. about 60% of the sweep angle θ or full extension ofthe second lock link 102 relative to the first lock link 101) where thetoggle link 105 is substantially in the position shown in FIG. 3B. Asshown in FIG. 3B, at about 60% of sweep angle θ of the second lock link102 (in other aspects, reverse rotation of the crank link may occurbefore or later than about 60% of sweep angle θ), the crank link 104 maybegin to rotate about toggle link pivot axis TLPA in direction R4relative to the first lock link 101, noting that the position of thecrank link 104 at the transition between rotation directions R3 and R4,in one aspect, defines the maximum length of the at least one biasingmember 106.

The configuration of the landing gear lock assembly 100 causes lostmotion in the toggle lock mechanism 103 during the transition of thecrank link 104 from rotation direction R3 to rotation direction R4, asevidenced in a comparison between FIGS. 3B and 3C (e.g. from about 60%of sweep angle θ to about 80-90% of sweep angle θ of the second locklink 102). During the lost motion of the landing gear lock assembly 100the at least one biasing member 106 substantially may not continue toextend or retract or, in other aspects, the extension/retraction of theat least one biasing member is significantly less than the travel of thesecond lock link 102 relative to the first lock link 101. For example,in one aspect, as the second lock link 102 rotates about link pivot axisLPA in rotation direction R1 from about 60% to about 90% of sweep angleθ (or in other aspects from about 60% to about 80% of sweep angleθ—e.g., the extended configuration of the at least one biasing member106 occurs at about 80% to about 90% of a sweep angle θ) the at leastone biasing member 106 may have an extended configuration that issubstantially equal to a length that is about 75% to about 100% of thefull rated extension length of the at least one biasing member 106. Inone aspect, the extended configuration may be about 80% or about 85% ofthe full rated extension length. In another aspect, the at least onebiasing member 106 may have an extended configuration that issubstantially equal to a length that is about 75% to about 100% of thelength of the at least one biasing member 106 defined by thebi-directional rotation of the crank link 104. In one aspect, theextended configuration may be about 80% or about 85% of the length ofthe at least one biasing member 106 defined by the bi-directionalrotation of the crank link 104.

In one aspect, the full rated extension length of the spring is thedesigned for/desired extended length of the spring that is calculatedusing the following formula:

FREL=LIH+(L/k).

FREL is the full rated extension length of the spring, L is the loadapplied to the spring, k is the spring rate, and LIH is the length ofthe extension spring inside the hooks of the extension spring.Alternatively, the full rated extension length of the spring may be themaximum length the spring can be extended to repeatedly whilemaintaining a predetermined service life.

In one aspect, the extended configuration of the at least one biasingmember 106 occurs at a brace angle α, of about 170 degrees, while inother aspects, the extended configuration of the at least one biasingmember 106 may occur at a brace angle α of more or less than about 170degrees.

In one aspect, a maximum force applied to the landing gear lock assembly100 by the at least one biasing member 106 is needed at about 80% toabout 90% of the full extension of the second lock link 102 to lock thelanding gear in an extended configuration. As noted above, the lostmotion of the toggle lock mechanism 103 maintains the at least onebiasing member 106 at about 75% to about 100% of its full ratedextension or maximum length (which means that 75% to about 100% of thespring stroke (and corresponding force) is utilized by the landing gearlock assembly 100, which is over about 15% more utilized spring strokethan the conventional landing gear lock discussed above. As describedherein, at about the full extension of the second lock link 102 relativeto the first lock link 101, the at least one biasing member 106 appliesa force to the crank link 104 of the toggle lock mechanism 103 to rotatethe toggle link 105 to an over-center position mechanically locking thelanding gear lock assembly 100 and the landing gear in the extendedconfiguration.

Referring now to FIGS. 1A-1C, 3A-3E, 4A-4C and 9, a method 900 foroperating, for example, main landing gear 1100A is illustrated. In oneaspect, the main landing gear 1100A is situated in an extended/unfoldedposition outside of the airframe 1118. While the main landing gear 1100Ais in the extended position, the landing gear lock assembly 100 is alsoin an extended and locked position as illustrated in FIG. 3E.

In order to retract the landing gear, for example after takeoff, asequence opposite that illustrated in FIGS. 3A-3E is initiated by, inone aspect, actuating an actuator 107 to apply force to the crank link104 of the toggle lock mechanism 103, such as by retracting theactuator, to rotate the crank link 104 of the toggle lock mechanism 103in rotation direction R3 about toggle lock pivot axis TLPA against thebiasing moment M of the at least one biasing member 106 causing amechanical unlocking (e.g., the unlocking of the over center lockedposition of the toggle link 105) of the second lock link 102 from thefully extended position illustrated in FIG. 3E and causing rotation ofthe second lock link 102 away from the fully extended positionillustrated in FIG. 3E (FIG. 9, Block 901). The actuator 107 isretracted to rotate the toggle lock mechanism 103 about the toggle lockpivot axis TLPA of the first lock link 101, causing rotation of thesecond lock link 102 in a direction substantially opposite rotationdirection R1 (FIG. 9, Block 902). As the second lock link 102 isrotated, the second lock link 102 folds relative to the first lock link101 in the direction substantially opposite the rotation direction R1(FIG. 9, Block 903). The toggle link 105 of the toggle lock mechanism103 rotates about second toggle link axis TA2 relative to the secondlock link 102, in a rotation direction that is substantially oppositerotation direction R2, to rotate the second lock link 102 to the fullyretracted position of the second lock link 102, illustrated in FIG. 3A,relative to the first lock link 101 (FIG. 9, Block 904). In one aspect,the landing gear actuator 1145 is actuated coincident with actuator 107to retract the landing gear into the airframe 1118.

As the landing gear lock assembly 100 retracts/folds to the fullyretracted position, the at least one biasing member 106 transitionsbetween relaxed and extended configurations in a manner substantiallysimilar to that described above when the landing gear lock assembly 100is extended/unfolded.

Examples of the present disclosure may be described in the context ofaircraft manufacturing and service method 1000 as shown in FIG. 10. Inother aspects, the examples of the present disclosure may be applied inany suitable industry, such as e.g. automotive, maritime and aerospace,With respect to aircraft manufacturing, during pre-production,illustrative method 1000 may include specification and design (FIG. 10,Block 1004) of aircraft 1102 and material procurement (FIG. 10, Block1006). During production, component and subassembly manufacturing (FIG.10, Block 1008) and system integration (FIG. 10, Block 1010) of aircraft1102 may take place, which may include manufacturing and installation ofthe landing gear lock assembly 100. Thereafter, aircraft 1102 may gothrough certification and delivery (FIG. 10, Block 1012) to be placed inservice (FIG. 10, Block 1014). While in service, aircraft 1102 may bescheduled for routine maintenance and service (FIG. 10, Block 1016).Routine maintenance and service may include modification,reconfiguration, refurbishment, etc. of one or more systems of aircraft1102, which may include installation of the landing gear lock assembly100 as described herein.

Each of the processes of illustrative method 1000 may be performed orcarried out by a system integrator, a third party, and/or an operator(e.g., a customer). For the purposes of this description, a systemintegrator may include, without limitation, any number of aircraftmanufacturers and major-system subcontractors; a third party mayinclude, without limitation, any number of vendors, subcontractors, andsuppliers; and an operator may be an airline, leasing company, militaryentity, service organization, and so on.

Apparatus(es) and method(s) shown or described herein may be employedduring any one or more of the stages of the manufacturing and servicemethod 1000. For example, components or subassemblies corresponding tocomponent and subassembly manufacturing (FIG. 10, Block 1008) may befabricated or manufactured in a manner similar to components orsubassemblies produced while aircraft 1102 is in service (FIG. 10, Block1014). Also, one or more examples of the apparatus(es), method(s), orcombination thereof may be utilized during production of the aircraft1102, for example, by substantially expediting assembly of or reducingthe cost of aircraft 1102. Similarly, one or more examples of theapparatus or method realizations, or a combination thereof, may beutilized, for example and without limitation, while aircraft 1102 is inservice (FIG. 10, Block 1014) and/or during maintenance and service(FIG. 10, Block 1016).

The following are provided in accordance with the aspects of the presentdisclosure:

A1. A landing gear lock assembly comprising:

a first lock link having a first end and a second end;a second lock link having a first end and a second end, the first end ofthe second lock link being rotatably coupled to the second end of thefirst lock link so that the first and second lock links unfold relativeto each other in a first rotation direction; anda toggle lock mechanism having a crank link and a toggle link rotatablycoupled to each other at a toggle link axis, the toggle link beingrotatably coupled to the second lock link, and the crank link beingrotatably coupled to the first lock link so that the toggle link rotatesrelative to the second lock link, in a second rotation directionopposite the first rotation direction, to rotate the second lock link toa fully extended position of the second lock link relative to the firstlock link;where rotation of the toggle link in the second rotation directionmechanically locks the second lock link in the fully extended position.

A2. The landing gear lock assembly of paragraph A1, further comprisingat least one biasing member coupled to both the first lock link and thecrank link.

A3. The landing gear lock assembly of paragraph A2, wherein the at leastone biasing member comprises two or more biasing members located on acommon side of the first lock link.

A4. The landing gear lock assembly of paragraph A3, wherein the two ormore biasing members are arranged in parallel.

A5. The landing gear lock assembly of paragraph A2, wherein the at leastone biasing member is in a substantially relaxed state when the secondlock link is in a fully retracted position.

A6. The landing gear lock assembly of paragraph A2, wherein the at leastone biasing member is in a substantially relaxed state when the secondlock link is in the fully extended position.

A7. The landing gear lock assembly of paragraph A2, wherein the at leastone biasing member comprises an extension spring.

A8. The landing gear lock assembly of paragraph A2, wherein the at leastone biasing member comprises a coil spring.

A9. The landing gear lock assembly of paragraph A1, further comprisingbut one set of biasing members coupled to both the first lock link andthe crank link, the but one set of biasing members being located on acommon side of the first lock link.

A10. The landing gear lock assembly of paragraph A9, wherein eachbiasing member in the but one set of biasing members is in a relaxedstate when the second lock link is in a fully retracted position.

A11. The landing gear lock assembly of paragraph A9, wherein eachbiasing member in the but one set of biasing members is in a relaxedstate when the second lock link is in the fully extended position.

A12. The landing gear lock assembly of paragraph A9, wherein the but oneset of biasing members is located on a side of the first lock linkopposite a sweep path of the second lock link.

A13. The landing gear lock assembly of paragraph A1, further comprisingat least one actuator having a first end coupled to the first lock linkand a second end coupled to the crank link.

A14. The landing gear lock assembly of paragraph A13, wherein the cranklink has a first end and a second end and a toggle lock pivot axisdisposed between the first end and second end of the crank link, thecrank link being rotatably coupled to the first lock link about thetoggle lock pivot axis and the at least one actuator is coupled to thefirst end of the crank link, the landing gear lock assembly furthercomprises at least one biasing member having a first end coupled to thefirst lock link and a second end coupled to the second end of the cranklink.

A15. The landing gear lock assembly of paragraph A14, wherein the togglelink is rotatably coupled to the crank link at the first end of thecrank link.

A16. The landing gear lock assembly of paragraph A13, wherein the firstlock link includes a recess, the at least one actuator being disposedwithin the recess.

A17. The landing gear lock assembly of paragraph A1, wherein the secondlock link is rotatably coupled to the first lock link at a link pivotaxis disposed between the first end and the second end of the secondlock link.

A18. The landing gear lock assembly of paragraph A1, wherein the firstend of the first lock link is configured for coupling to a landing gearshock strut and the second end of the second lock link is configured forcoupling to one of a landing gear drag brace or a landing gear sidebrace.

A19. The landing gear lock assembly of paragraph A1, wherein the firstend of the first lock link is configured for coupling to one of alanding gear drag brace or a landing gear side brace and the second endof the second lock link is configured for coupling to a landing gearshock strut.

A20. The landing gear lock assembly of paragraph A1, wherein the firstend of the first lock link is configured for coupling to an aircraftframe and the second end of the second lock link is configured forcoupling to one of a landing gear drag brace or a landing gear sidebrace.

A21. The landing gear lock assembly of paragraph A1, wherein the cranklink includes a toggle stop configured to contact the toggle link at anover center locked position of the landing gear lock assembly.

A22. The landing gear lock assembly of paragraph A1, wherein the landinggear lock assembly comprises a self-contained locking assemblyfunctionally mounted to an aircraft by only the first lock link andsecond lock link.

A23. The landing gear lock assembly of paragraph A1, wherein the cranklink and the toggle link of the toggle lock mechanism are configured tounfold in a direction opposite the first rotation direction.

B1. A method of assembling a landing gear lock assembly, the methodcomprising:

rotatably coupling a second end of a first lock link to a first end of asecond lock link so that the first and second lock links unfold relativeto each other in a first rotation direction;rotatably coupling a crank link and a toggle link of a toggle lockmechanism to each other;rotatably coupling the toggle link to the second lock link and rotatablycoupling the crank link to the first lock link so that the toggle linkrotates relative to the second lock link, in a second rotation directionopposite the first rotation direction, to rotate the second lock link toa fully extended position of the second lock link relative to the firstlock link; and wherein the second lock link mechanically locks in thefully extended position with rotation of the toggle link in the secondrotation direction.

B2. The method of paragraph B 1, further comprising coupling at leastone biasing member to both the first lock link and the crank link.

B3. The method of paragraph B 1, further comprising coupling but one setof biasing members to both the first lock link and the crank link sothat the but one set of biasing members are located on a common side ofthe first lock link.

B4. The method of paragraph B 1, further comprising coupling a first endof at least one actuator to the first lock link and a second end of theat least one actuator to the crank link.

B5. The method of paragraph B4, further comprising disposing the atleast one actuator within a recess of the first lock link.

B6. The method of paragraph B 1, further comprising:

coupling at least one actuator to both a first end of the crank link andthe first lock link; andcoupling at least one biasing member to both the first lock link and asecond end of the crank link, where the first and second ends of thecrank link are disposed on opposite sides of a toggle lock pivot axis.

B7. The method of paragraph B6, wherein rotatably coupling the cranklink and the toggle link of the toggle lock mechanism to each othercomprises rotatably coupling the toggle link to the crank link at thefirst end of the crank link.

B8. The method of paragraph B 1, wherein rotatably coupling a second endof a first lock link to a first end of a second lock link comprisescoupling the second lock link to the first lock link at a link pivotaxis disposed between the first end and a second end of the second locklink.

B9. The method of paragraph B 1, further comprising coupling a first endof the first lock link to a landing gear shock strut and coupling thesecond end of the second lock link to one of a landing gear drag braceor a landing gear side brace.

C1. A method for operating a landing gear, the method comprising:

extending an actuator to rotate a toggle lock mechanism about a togglelock pivot axis of a first lock link, causing rotation of a second locklink that is rotatably coupled to the first lock link so thatthe second lock link unfolds relative to the first lock link in a firstrotation direction, anda toggle link of the toggle lock mechanism rotates relative to thesecond lock link, in a second rotation direction opposite the firstrotation direction, to rotate the second lock link to a fully extendedposition of the second lock link relative to the first lock link; andapplying a force to a crank link of the toggle lock mechanism with atleast one biasing member to further rotate the toggle lock mechanism inthe second rotation direction causing rotation of the second lock linkto the fully extended position and causing a mechanical locking of thesecond lock link in the fully extended position;wherein the toggle link couples the crank link to the second lock link,the actuator is coupled to both the first lock link and the crank link,and the at least one biasing member is coupled to both the first locklink and the crank link.

C2. The method of paragraph C1, wherein applying the force to the cranklink of the toggle lock mechanism with the at least one biasing membercomprises applying the force with at least two biasing members.

C3. The method of paragraph C1, wherein applying the force to the cranklink of the toggle lock mechanism with the at least one biasing membercomprises applying the force with but one set of biasing members on acommon side of the first lock link.

C4. The method of paragraph C1, wherein applying the force to the cranklink of the toggle lock mechanism with the at least one biasing membercomprises applying the force with but one set of biasing members locatedon a side of the first lock link opposite a sweep path of the secondlock link.

C5. The method of paragraph C1, wherein extending the actuator applies aforce to the crank link on a first end of the crank link and the forceapplied to the crank link by the at least one biasing member is appliedto a second end of the crank link, where the first and second ends ofthe crank link are located on opposite sides of a toggle lock pivotaxis.

C6. The method of paragraph C1, wherein the crank link and the togglelink of the toggle lock mechanism are configured to unfold in adirection opposite the first rotation direction.

C7. The method of paragraph C1, wherein the mechanical locking of thesecond lock link in the fully extended position is caused by an overcenter locking of the toggle link and crank link.

C8. The method of paragraph C7, further comprising retracting theactuator to unlock the over center locking of the toggle link and cranklink to retract the second lock link to the fully retracted position.

C9. The method of paragraph C1, further comprising transitioning the atleast one biasing member from a substantially relaxed configuration toan extended configuration and back to a substantially relaxedconfiguration during extension of the second lock link from a fullyretracted position to the fully extended position.

C10. The method of paragraph C9, wherein the extended configuration isabout 75% to about 100% of a length of the at least one biasing memberat full rated extension of the at least one biasing member.

C11. The method of paragraph C10, wherein the extended configurationoccurs at about 80% to about 90% of a sweep angle of the second locklink from a fully retracted position to the fully extended position.

C12. The method of paragraph C, wherein the actuator is extended bygravitational force acting on the landing gear.

D1. A method for operating a landing gear, the method comprising:

extending an actuator to apply a force to a crank link of a toggle lockmechanism to rotate the toggle lock mechanism in a first rotationdirection against a biasing force of at least one biasing member causinga mechanical unlocking of a second lock link from the fully extendedposition and causing rotation of the second lock link away from thefully extended position;retracting the actuator to rotate the toggle lock mechanism about atoggle lock pivot axis of a first lock link, causing rotation of thesecond lock link that is rotatably coupled to the first lock link sothatthe second lock link folds relative to the first lock link in a secondrotation direction, anda toggle link of the toggle lock mechanism rotates relative to thesecond lock link, in the first rotation direction opposite the secondrotation direction, to rotate the second lock link to a fully retractedposition of the second lock link relative to the first lock link; andwherein the toggle link couples the crank link to the second lock link,the actuator is coupled to both the first lock link and the crank link,and the at least one biasing member is coupled to both the first locklink and the crank link.

D2. The method of paragraph D1, wherein the biasing force applied to thecrank link of the toggle lock mechanism with the at least one biasingmember is applied with at least two biasing members.

D3. The method of paragraph D1, wherein the biasing force applied to thecrank link of the toggle lock mechanism with the at least one biasingmember is applied with but one set of biasing members on a common sideof the first lock link.

D4. The method of paragraph D1, wherein the biasing force applied to thecrank link of the toggle lock mechanism with the at least one biasingmember is applied with but one set of biasing members located on a sideof the first lock link opposite a sweep path of the second lock link.

D5. The method of paragraph D1, wherein retracting the actuator appliesa force to the crank link on a first end of the crank link and the forceapplied to the crank link by the at least one biasing member is appliedto a second end of the crank link, where the first and second ends ofthe crank link are located on opposite sides of a toggle lock pivotaxis.

D6. The method of paragraph D1, wherein the crank link and the togglelink of the toggle lock mechanism are configured to fold in a directionopposite the second rotation direction.

D7. The method of paragraph D1, wherein the mechanical unlocking of thesecond lock link from the fully extended position is caused by releasingan over center locking of the toggle link and crank link.

D8. The method of paragraph D1, further comprising transitioning the atleast one biasing member from a substantially relaxed configuration toan extended configuration and back to a substantially relaxedconfiguration during retraction of the second lock link from the fullyextended position to a fully retracted position.

D9. The method of paragraph D8, wherein the extended configuration isabout 75% to about 100% of a length of the at least one biasing memberat full rated extension of the at least one biasing member.

D10. The method of paragraph D9, wherein the extended configurationoccurs at about 20% to about 10% of a sweep angle of the second locklink from the fully extended position to the fully retracted position.

In the figures, referred to above, solid lines, if any, connectingvarious elements and/or components may represent mechanical, electrical,fluid, optical, electromagnetic, wireless and other couplings and/orcombinations thereof. As used herein, “coupled” means associateddirectly as well as indirectly. For example, a member A may be directlyassociated with a member B, or may be indirectly associated therewith,e.g., via another member C. It will be understood that not allrelationships among the various disclosed elements are necessarilyrepresented. Accordingly, couplings other than those depicted in thedrawings may also exist. Dashed lines, if any, connecting blocksdesignating the various elements and/or components represent couplingssimilar in function and purpose to those represented by solid lines;however, couplings represented by the dashed lines may either beselectively provided or may relate to alternative examples of thepresent disclosure. Likewise, elements and/or components, if any,represented with dashed lines, indicate alternative examples of thepresent disclosure. One or more elements shown in solid and/or dashedlines may be omitted from a particular example without departing fromthe scope of the present disclosure. Environmental elements, if any, arerepresented with dotted lines. Virtual (imaginary) elements may also beshown for clarity. Those skilled in the art will appreciate that some ofthe features illustrated in the figures, may be combined in various wayswithout the need to include other features described in the figures,other drawing figures, and/or the accompanying disclosure, even thoughsuch combination or combinations are not explicitly illustrated herein.Similarly, additional features not limited to the examples presented,may be combined with some or all of the features shown and describedherein.

In FIGS. 7-10, referred to above, the blocks may represent operationsand/or portions thereof and lines connecting the various blocks do notimply any particular order or dependency of the operations or portionsthereof. Blocks represented by dashed lines indicate alternativeoperations and/or portions thereof. Dashed lines, if any, connecting thevarious blocks represent alternative dependencies of the operations orportions thereof. It will be understood that not all dependencies amongthe various disclosed operations are necessarily represented. FIGS. 7-10and the accompanying disclosure describing the operations of themethod(s) set forth herein should not be interpreted as necessarilydetermining a sequence in which the operations are to be performed.Rather, although one illustrative order is indicated, it is to beunderstood that the sequence of the operations may be modified whenappropriate. Accordingly, certain operations may be performed in adifferent order or simultaneously. Additionally, those skilled in theart will appreciate that not all operations described need be performed.

In the foregoing description, numerous specific details are set forth toprovide a thorough understanding of the disclosed concepts, which may bepracticed without some or all of these particulars. In other instances,details of known devices and/or processes have been omitted to avoidunnecessarily obscuring the disclosure. While some concepts will bedescribed in conjunction with specific examples, it will be understoodthat these examples are not intended to be limiting.

Unless otherwise indicated, the terms “first,” “second,” etc. are usedherein merely as labels, and are not intended to impose ordinal,positional, or hierarchical requirements on the items to which theseterms refer. Moreover, reference to, e.g., a “second” item does notrequire or preclude the existence of, e.g., a “first” or lower-numbereditem, and/or, e.g., a “third” or higher-numbered item.

Reference herein to “one example” means that one or more feature,structure, or characteristic described in connection with the example isincluded in at least one implementation. The phrase “one example” invarious places in the specification may or may not be referring to thesame example.

As used herein, a system, apparatus, structure, article, element,component, or hardware “configured to” perform a specified function isindeed capable of performing the specified function without anyalteration, rather than merely having potential to perform the specifiedfunction after further modification. In other words, the system,apparatus, structure, article, element, component, or hardware“configured to” perform a specified function is specifically selected,created, implemented, utilized, programmed, and/or designed for thepurpose of performing the specified function. As used herein,“configured to” denotes existing characteristics of a system, apparatus,structure, article, element, component, or hardware which enable thesystem, apparatus, structure, article, element, component, or hardwareto perform the specified function without further modification. Forpurposes of this disclosure, a system, apparatus, structure, article,element, component, or hardware described as being “configured to”perform a particular function may additionally or alternatively bedescribed as being “adapted to” and/or as being “operative to” performthat function.

Different examples of the apparatus(es) and method(s) disclosed hereininclude a variety of components, features, and functionalities. Itshould be understood that the various examples of the apparatus(es) andmethod(s) disclosed herein may include any of the components, features,and functionalities of any of the other examples of the apparatus(es)and method(s) disclosed herein in any combination, and all of suchpossibilities are intended to be within the scope of the presentdisclosure.

Many modifications of examples set forth herein will come to mind to oneskilled in the art to which the present disclosure pertains having thebenefit of the teachings presented in the foregoing descriptions and theassociated drawings.

Therefore, it is to be understood that the present disclosure is not tobe limited to the specific examples illustrated and that modificationsand other examples are intended to be included within the scope of theappended claims. Moreover, although the foregoing description and theassociated drawings describe examples of the present disclosure in thecontext of certain illustrative combinations of elements and/orfunctions, it should be appreciated that different combinations ofelements and/or functions may be provided by alternative implementationswithout departing from the scope of the appended claims. Accordingly,parenthetical reference numerals in the appended claims, if any, arepresented for illustrative purposes only and are not intended to limitthe scope of the claimed subject matter to the specific examplesprovided in the present disclosure.

What is claimed is:
 1. A method for operating a landing gear, the methodcomprising: extending an actuator to apply a force to a crank link of atoggle lock mechanism to rotate the toggle lock mechanism in a firstrotation direction against a biasing force of at least one biasingmember causing a mechanical unlocking of a second lock link from a fullyextended position and causing rotation of the second lock link away fromthe fully extended position; retracting the actuator to rotate thetoggle lock mechanism about a toggle lock pivot axis of a first locklink, causing rotation of the second lock link that is rotatably coupledto the first lock link so that the second lock link folds relative tothe first lock link in a second rotation direction, and a toggle link ofthe toggle lock mechanism rotates relative to the second lock link, inthe first rotation direction opposite the second rotation direction, torotate the second lock link to a fully retracted position of the secondlock link relative to the first lock link; and wherein: the first locklink and the second lock link are distinct from a landing gear shockstrut of the landing gear, and the toggle link couples the crank link tothe second lock link, the actuator is coupled to both the first locklink and the crank link, and the at least one biasing member is coupledto both the first lock link and the crank link.
 2. The method of claim1, wherein the biasing force applied to the crank link of the togglelock mechanism with the at least one biasing member is applied with atleast two biasing members.
 3. The method of claim 1, wherein the biasingforce applied to the crank link of the toggle lock mechanism with the atleast one biasing member is applied with but one set of biasing memberson a common side of the first lock link.
 4. The method of claim 1,wherein the biasing force applied to the crank link of the toggle lockmechanism with the at least one biasing member is applied with but oneset of biasing members located on a side of the first lock link oppositea sweep path of the second lock link.
 5. The method of claim 1, whereinretracting the actuator applies a force to the crank link on a first endof the crank link and the force applied to the crank link by the atleast one biasing member is applied to a second end of the crank link,where the first and second ends of the crank link are located onopposite sides of a toggle lock pivot axis.
 6. The method of claim 1,wherein the crank link and the toggle link of the toggle lock mechanismare configured to fold in a direction opposite the second rotationdirection.
 7. The method of claim 1, wherein the mechanical unlocking ofthe second lock link from the fully extended position is caused byreleasing an over center locking of the toggle link and crank link. 8.The method of claim 1, further comprising transitioning the at least onebiasing member from a substantially relaxed configuration to an extendedconfiguration and back to a substantially relaxed configuration duringretraction of the second lock link from the fully extended position to afully retracted position.
 9. The method of claim 8, wherein the extendedconfiguration is about 75% to about 100% of a length of the at least onebiasing member at full rated extension of the at least one biasingmember.
 10. The method of claim 9, wherein the extended configurationoccurs at about 20% to about 10% of a sweep angle of the second locklink from the fully extended position to the fully retracted position.11. An aircraft comprising: a landing gear having a landing gear shockstrut; and a landing gear lock assembly for the landing gear, thelanding gear lock assembly comprising: a first lock link having a firstend and a second end; a second lock link having a first end and a secondend, the first end of the second lock link being rotatably coupled tothe second end of the first lock link so that the first and second locklinks unfold relative to each other in a first rotation direction, whereboth the first lock link and the second lock link are distinct from thelanding gear shock strut; and a toggle lock mechanism having a cranklink and a toggle link rotatably coupled to each other at a toggle linkaxis, the toggle link being rotatably coupled to the second lock link,and the crank link being rotatably coupled to the first lock link sothat the toggle link rotates relative to the second lock link, in asecond rotation direction opposite the first rotation direction, tomechanically lock the second lock link in a fully extended position. 12.The aircraft of claim 11, further comprising at least one biasing membercoupled to both the first lock link and the crank link.
 13. The aircraftof claim 12, wherein the at least one biasing member comprises two ormore biasing members located on a common side of the first lock link.14. The aircraft of claim 12, wherein the at least one biasing member isin a substantially relaxed state when the second lock link is in a fullyretracted position.
 15. The aircraft of claim 12, wherein the at leastone biasing member is in a substantially relaxed state when the secondlock link is in the fully extended position.
 16. The aircraft of claim11, further comprising at least one actuator having a first end coupledto the first lock link and a second end coupled to the crank link. 17.The aircraft of claim 16, wherein the crank link has a first end and asecond end and a toggle lock pivot axis disposed between the first endand second end of the crank link, the crank link being rotatably coupledto the first lock link about the toggle lock pivot axis and the at leastone actuator is coupled to the first end of the crank link, the landinggear lock assembly further comprises at least one biasing member havinga first end coupled to the first lock link and a second end coupled tothe second end of the crank link.
 18. The aircraft of claim 16, whereinthe first lock link includes a recess, the at least one actuator beingdisposed within the recess.
 19. The aircraft of claim 11, wherein thelanding gear lock assembly comprises a self-contained locking assemblyfunctionally mounted to an aircraft by only the first lock link andsecond lock link.
 20. The aircraft of claim 11, wherein the crank linkand the toggle link of the toggle lock mechanism are configured tounfold in a direction opposite the first rotation direction.